Lifting jack



J. C. KOPF.

LIFTING JACK. APPLICATION FILED MAR-11,1921.

1,410,579., Patented Mar- 28, 1922;v

2 SHEETS-SHEET 1.

J9 nvmvro/r 19 17 3 7W V sire MANUFACTURING COMPANY; F PITTSBURGH, PENNSYLVANIA, A CORPORA- TION OF PENNSYLVANIA.

I 'LIFTING JACK.

l gilih579.

T 0 all 107mm it may concern:

Be it known that I, JOHN C. Kori, a citi zen of the United'States, and a resident of the borough of Bellevue in the countyoi Allegheny and State 0ii'P-ennsylvania,-have -invented anew and useful Lifting Jack, of

which the following is a specification.

journal-box or journal jacks. These jacks are required to be -used under varying conditions of distance between' the chance points of support along {the track and the jacking points on thecars, so'that frequently after litting it is'found that the lift is not high enough. and that a block inust be-used, necessitating lowering-the load and -re-j acking while at other times there may" be-di-tli- 0 culty 1nintroducingthe jack atall. Because of these conditions, the V geneal endeavor in the design of ournal-box 'yacks has been to keep the fixed height down-as 'inuch as;

possible while obtaining the maximum amount of lift, a gain of even a part of an inch -berngnn ater1al. The purpose. of this invention is to effect a very marked advance .inthis direction at thesame time securing a construction of notable lightness, strength, o. and economy oit-inanufa'cture, all iieatures of special importance in these small, much-used acks.

p A further ob ectis to provide an improved carryingh'andlewhich-serves adou .5 :ble function.

"In th accompanyingdrawings, forming Fig. 3.is a horizontal section on the line 33 of Fig. l.

The jack has a shell or hollow closed frame 1 having a broad base and a narrow top. the latter formed with a cylindrical hearing 2. Said frame is composed of two parts. the body or shell proper, forming the sides, and a base-plate 3, which is screwed into an internally screw-threaded bottom rim & on the wide lower end of the shell. The disk or plate is formed with a raised screw-threaded rim 5 which enters the rim of the shell, and an outwardly projecting flange 6 to abut the bottom of the shell. A. pin 7 locks the plate in place.

Fig. 2 is a plan view-of the base plate and Specification of Letters Patent. 'pat ted Di 2% 192g, Application filed March 11;1921. Serial No. 451,495.

A hollow cylindrical ram-S, desirably con guided-in the bearing 2. A customary nut 1 10 secured in the lower end of the ram coop- 'erates with a screw 11 rotatably supported on the base and extending upward within The invention relates to ball-bearing screw-jacks and more particularly to the" lOclass of jacksused on railroads, known as the ram. On the lower end of the screw is a bevel gem-l2. meshed by adrivmg gear 13on' a horizontal operating shaft 14 jourwhich the screw and gear are set above the base. An object of'the invention is to practically eliminate this spacing by close coupling the parts without the intervention-0t ball-plates. thus reducing the spacing substantially to that of the balls themselves,

which balls as heretofore are partly received in ball races or pockets. In this way a decidedly longer screw and ram, compared to the height of the jack lowered. can be tlHplOyeCl. and thus a greater lifting range secured with equal or less initial heigh'.

This is accomplished in the first place by a specialconstructionot the base-plate This plate l make of a drop-forging. having the characteristic toughness 01"? such torgings, and with a ball-race groove 16 pressed directly in its top. The plate is so formed as to present sutlicient thickness in the annular region 17 containing the hall-race to withstand the crushing torce of the load, in-

*ardlyof which. and outwardly between the same and the peripheral region containing 9 the screw rim fillfl'tllml'lllelli flange 6. are

thin connecting regions 18 and 1.9. Such abasc-plate while eminently desirable for its strength and lightness. and its relatively small height. is unsuitable because the balls would press into the raceway and render the bearing inoperative. This I find can be overcome and adequate wearing support secured for the balls, heretoii'ore afforded by the special steel ball-plate, by forming a hardened ball-race directly on and from the tough body of the plate. Such an integral ball-race while slight in thickness as compared with a separate ball-plate, can nevertheless be made to extend deeply enough into the forging by ordinary methods of case-hardening to carry the concentrated load pressure of the balls without breakin Ther is thus obtained a ball-race too slight in itself to endure the stresses but backed and rendered operative by the body of the structurally advantageous base element. However, because of the screw joint, which is the most durable form of connection between the base and shell, and the most advantageous in respect to keeping down the fixed height, it is not practicable to caseharden the entire surface, or if'it is, the hardened part must be removed where the screw-threads 5 are formed. Preferably, after smoothing the groove 16,1 electro-plate the base-plate, and then brush off the plating from the groove. Thus, in the hardening process the plating where it remains, and particularly at the region 5, prevents the forged metal from becoming, hardened, while the ball-race isformed as described.

The upper ball-race 21 is formed directly on the bottom of the gear 12. This gear is preferably also a drop-forging case-hardened, but might be made. less economically,

from steel sufficiently hard throughout.

Jacks of this type are in frequent use in inspecting and removing journal brasses, and must be carried substantial distances by hand, perhaps the length of a long freight. Li'ghtness and a convenient carryinghandle are therefore important considerations. The invention provides such a handle, which also serves as a means to keep the ram 8 from turning in the bearing 2. The said handle comprises a ball 22 adapted to be swung vertically above the top of the jack, and

having inturned ends 23 which are swiveled 1n opposed horizontal openings of the top bearing portion 2 of the'shell. One of said ends, as seen at the left of Fig. 1, projects through the shell into a longitudinal groove 24:1 in the exterior of the ram, thus acting as a :ey.

The numerous advantages of a jack constructed according to my invention will be apparent to those skilled in the art. The elimination of the ball-plates, it maybe noted, not only produces a large saving in height and reduces the weight to be carried ran s-re about, but is also a substantial econon1y,'as

these special steel plates are normally a material item of cost, and frequently after being machined develop defects in the heat treatment, causing them to be discarded after the work has been done upon them. My bottom element is susceptible of rapid and cheap production, and afiords'both a baseplate and a race-way, embodied in a very light and durable form. The elimination of the lower ball-plate is. of further advantage in that these plates have to be fitted fairly closely in their recesses, and it not infrequently happens that they do not seat flat upon the bottoms, because of a fillet at the corners or some unnoticed obstruction in the recess, causing the plate to break when load is applied. These difficulties are now avoided and the manufacture materially simplified by my special base-plate construction having the ball-race on it.

hat Iclaim as new is:

l. A lifting jack having a shell, a rain guided in the top of the shell, a rotary screw within theram for actuating the same and 7 having agear on its lowerend, a base-plate screwed into the bottom of the shell, and balls interposed between the base-plate and gear, said base-plate having a tough body with an integral hardened ball-race" formed thereon I and a peripheral screw-thread formed of the unhardened body.

2. A lifting jack-having a shell, a ram guided in the top of the shell, a rotary screw within the ram for actuating the same and having a gear on its lower. end, abase plate secured to the bottom of theshell, and balls interposed between the base-plate and gear, said base-plate being'adrop-forging having an integral hardened ball-race formed there- In a lifting jack, the combination of a shell having a top bearing, a screw-operated ram slidable in said bearing and provided 

